Dialyzer apparatus and method



Dec. 23, 1969 w. HERRMANN ET AL 3,485,751

DIALYZER APPARATUS AND METHOD Filed Jan. 6. 1967 I3 WALTER L. HE RRMANN LEON R. SPADONI INVENTOR.

ATTORNEYS 'nited States Patent 3,485,751 DIALYZER APPARATUS AND METHOD Walter L. Herr-mama, 3845 49th NE., Seattle, Wash. 98105, and Leon R. Spadoui, 1530 184th NE, Bellevue, l/Vash. 98004 Filed Jan. 6, 1967, Ser. No. 607,848 Int. Cl. BOld 13/00 US. Cl. 2143-22 8 Claims ABSTRACT OF THE DISCLOSURE A device for performing a dialysis on liquid samples such as urine to remove water and other molecules and particles of the same general size range and smaller, and a method of concentrating urine samples by dialysis without removing or disturbing certain protein molecules useful in medical testing; notably human chorionic gonadotropin, thereby enabling positive diagnosis of pregnancy by standard pregnancy tests only a few days after the first missed menses.

The present invention relates in general to a device for performing a dialysis on liquid samples such as urine to remove water and other molecules and particles of the same general size range and smaller. The invention also relates to a method of concentrating urine samples by dialysis without removing or disturbing certain protein molecules useful in medical testing; notably human chorionic gonadotropin, thereby enabling positive diagnosis of pregnancy by standard pregnancy tests only a few days after the first missed menses.

Accordingly, the object of the present invention is to provide a simplified and inexpensive dialyzer apparatus and a method of concentrating urine samples by dialysis without removing certain protein molecules utilized in various medical tests and significantly, the test for the presence of chorionic gonadotropin.

Other and more particular objects and advantages of the present invention will be apparent to those skilled in the art from the following specification and claims and from the accompanying drawings wherein:

DESCRIPTION OF DRAWINGS FIG. 1 is a partially sectioned elevational view of the dialyzer according to the present invention; and

FIG. 2 is a cross-sectional view taken along lines 22 of FIG. 1.

DESCRIPTION OF INVENTION Referring now to the drawings wherein like reference numerals indicate identical parts in the various views, and referring especially to FIG. 1, the dialyzer generally comprises an outer tubular body 1, an inner tubular member 2 of a smaller diameter located within the tube 1 and a Y-tubing 3 sealed with relation to the outside tube 1 and communicating with the inner tube 2 for the introduction of the test sample into the inner tube.

As aforementioned, the apparatus of the present invention comprises a dialyzer which functions to separate or remove water molecules as well as certain other molecules of that general size range and smaller for the purpose of concentrating the urine sample and preserving certain protein molecules useful in medical testing, principally the human chorionic gonadotropin molecule utilized in standard pregnancy tests.

The sample containing tube 2, by way of example and not limitation, may comprise a cellophane tube approximately inch in diameter or may be composed of any other material suitable for providing a semi-permeable membrane for urine dialysis. The sample tube is, of

3,485,751 Patented Dec. 23, 1969 course, pliable and flexible, a feature which contributes to the effectiveness of the device as will presently be explained. The terms dialysis as used in this specification is intended to mean the process of separating compounds or materials by the difference in their diffusion rates through a semi-permeable membrane. The tube 2 is closed at its bottom end and this may be accomplished by simply forming a knot 4 in the bottom of the tube section as illustrated.

The Y-tubing 3 may be any suitable semi-rigid plastic tubing having inlet stems 6 and 7 and an outlet stem 8. The outlet stem 8 will be of a suitable diameter for insertion within the open upper end of the tube 2. In order to seal the tube 2 to the stem 8, a layer of adhesive tape or the like 9 may be tightly wrapped about the stem and the upper end of the tube 2. In the alternative, and if the materials are compatible, the upper end of the tube may be sealed to the stem 8 by an adhesive, a solvent or conceivably by fusing the materials with heat.

One inlet stem 6 of the Y-tube 3 may be provided with a removable plastic cap 11, the purpose of which will be presently described. The other stem 7 is provided with a conventional rubber diaphragm 12 of the type suitable for receiving a syringe needle for injecting the sample into the inner tube 2. The Y-tubing 3 and diaphragm 12 are commonly known and commercially available apparatus used by laboratory technicians.

The outer tube or bag 1 may be made of a clear film substance which is water proof and moisture resistant and which will preferably remain pliable over a long period of time. A recommended material is a film comprising a layer of fluorohalocarbon laminated to polyethylene and known commercially as Aclar film. The bottom end end of the tube 1 is closed and sealed and this may be accomplished by simply folding .the end and applying a suitable tape such as the tap 13 shown in FIG. 1. The upper end of the tube 1 is fitted over the stem 8 and is sealed thereabout by means of several layers of tape 14. Any equivalent means of sealing the tube 1 to the stem 8 of the Y-tubing will suffice, however.

The outer tube 1 is filled with a powdered substance having a high aifinity for water. The powder 16 substantially surrounds and covers the entire outer surface of the inner tube 2. The powder, of course, stimulates the diffusion of water molecules through the semi-permeable membrane provided by the wall of the inner tube 2. Although many substances would suflice for absorbing the water molecules, a recommended compound is the sodium salt of carboxymetheyl cellulose which is commonly known and commercially available as Aquacide.

To assemble the dialyzer apparatus, the tubing 2 comprising the scmi-permeable membrane is cut to a length of approximately 17 inches and one end thereof is sealed by tieing at least one knot as close to the end as possible as illustrated at 4 in FIG. 1. The object is to provide a length of tubing 2 which will accommodate approximately 10 cc. of urine sample. The opposite end of the tubing 2 is then opened and the outlet stem 8 of the Y-tubing 3 is carefully inserted so as not to puncture the tube 2. The upper end of the tube 2 may then be sealed to the stem 8 by means of the tape 9 or any other suitable means of sealing. A section of the outer tubing material 1 is then cut to a length slightly longer than the tube 2. The tube 2 is then inserted within the tube 1 and the tube 1 is sealed about the stem 8 by means of the tape 14 for example, or any other suitable means for sealing. The powder 16 may then be introduced into the tube 1 and about the dialysis tube 2. Approximately 15 grams of the powder is recommneded for the size tube under discussion and a funnel or the like may be used to introduce the powder. The open end of the tube 1 is then folded and sealed with the tape 13 or other suitable sealing means and the dialyzer is complete.

A dialyzer utilizing the inch tube approximately 17 inches in length will accommodate approximately cc. of urine sample which is introduced into the tube by means of a syringe needle which is inserted through the diaphragm 12 in a conventional manner. In the event that some of the sample remains in the Y-tubing 3, the cap 11 may be removed to allow the sample to drain down into the inner tube. The cap 11 should then be replaced.

After the sample has been injected into the tube 2, the tube is manipulated until the absorbent powder 16 uniformly covers the inner tube containing the sample. It is recommended that the unit then be placed in a horizontal position at room temperature for approximately one hour after which the unit should be again manipulated to redistribute the absorbent powder around the inner tube to allow for maximum concentration. The pliability of both the inner and outer tubes allows a greater volume of the absorbent powder to be brought into contact with the surface of the tube 2 and thus greatly speeds up the process. It may also be noted that, as fluids are withdrawn from the tube 2, the tube collapses and inherently causes the powder adjacent its surface to be redistributed thus speeding the process. The unit should then be allowed to set for another 30 to 45 minutes depending upon the amount of absorbent powder used. When the sample is ready for removal, the unit is held vertical with the Y-tube end held downwardly to allow the concentrated sample to accumulate so as to facilitate its removal. The sample is removed by reinserting the needle and syringe through the rubber diaphragm 12 to withdraw the sample. The volume of the sample should be in the neighborhood of 0.25 to 1.0 cc. In the event that the sample exceeds 1.0 cc., it should be reinjected and allowed to further concentrate. The concentrated sample is then ready for testing for chorionic gonadotropin or other related biologic substances.

Utilizing unconcentrated urine samples the standard pregnancy tests presently being practiced usually do not detect HCG before ten to fourteen days after the first missed menstrual period. Commonly known methods of concentrating urine samples, such as by heating and evaporating or evaporation at room temperature, are unsuitable either because of the length of the complexity and time involved or because of the destructive efiects on protein molecules in the sample, such as HCG, rendering the sample unfit for testing. With the present method of concentrating urine samples, it has been found the pregnancies can be detected within a few days after the first missed menses. Although the conventional pregnancy tests on unconcentrated urine may be generally satisfactory, in certain instances it becomes important and, indeed, necessary to diagnose pregnancy at an early date. Not only is this important from the standpoint of convenience to the patient, but oiftimes early abortions may be prevented if diagnosis is early enough.

From the foregoing, it will be obvious to those skilled in the art that the present invention provides new and unobvious results in dialyzer apparatus and also in the method of concentrating urine samples without destruction of protein molecules valuable in certain medical testing procedures.

What I claim is:

1. Apparatus for concentrating liquid samples com- 6 prising a semi-permeable membrane, a pliable thin walled envelope sealed about said sample container and forming a chamber therebet-ween, and a quantity of absorbent powder within said chamber in contact with the major portion of the outer surface of said sample container.

2. Apparatus for concentrating liquid samples comprising; a closed tubular sample container, closure means on one end of said sample tube adapted to permit introduction of a quantity of sample to be concentrated, a second closed tubular container surrounding said sample container, and :a quantity of absorbent powder within said second tubular container in contact with the outer surface of the sample container, said sample container being composed of thin pliable material and comprising a semi-permeable membrane and said second tubular container being composed of thin pliable material forming a moisture tight seal about said absorbent powder.

3. The apparatus according to claim 2 wherein said closure means comprises; a rigid hollow tube one end of which is sealed to said sample tube and forms an inlet passage communicating therewith, a puncturable membrane across the other end of said hollow tube, second passage means communicating with said hollow tube, and a removable closure member for said passage means.

4. The method of concentrating a liquid sample comprising; placing a small quantity of said sample within a closed pliable container comprising a semi-permeable membrane, and inducing diffusion of water and other substances through said membrane by holding an absorbent powder having a high aflinity for water on the surface of said membrane.

5. The method according to claim 4 wherein; said powder is held in a pliable envelope and contacts the major portion of the surface of said membrane.

'6. The method of claim 5 including coupling said pliable container to a rigid hollow tube having a puncturable membrane across an open end through which said sample is injected to place the sample into the pliable container and coupling said envelope to said tube over said container and inserting said powder between said container and envelope through an end of the envelope opposite to the end coupled to said tube.

7. The method according to claim 5 including manipulating said container and said envelope to redistribute said powder.

8. The method according to claim 7 wherein said sample comprises urine and said membrane is chosen to permit water and other electrolytes to readily diffuse thereacross and to restrict the diffusion of chorionic gonadotropin molecules.

References Cited UNITED STATES PATENTS 2,664,395 12/1953 Marchand 210321 2,687,997 8/1954 Marchand 2lO-321 2,734,017 2/1956 Wettstein et al. 21022 X 3,062,737 11/1962 Azorlosa et a1. 2l022 3,228,877 1/1966 Mahoin 2l032l X 3,367,787 2/ 1968 Thijssen et al 210-22 X REUBEN FRIEDMAN, Primary Examiner F. A. SPEAR, JR., Assisant Examiner US. Cl. X.R. 210321 

